Penetration of the dorsal screw when treating
distal radius fractures with volar locking plates is an avoidable complication
that causes lesions of the extensor tendon in between 2% and 6%
of patients. We examined axial fluoroscopic views of the distal
end of the radius to observe small amounts of dorsal screw penetration,
and determined the ideal angle of inclination of the x-ray beam
to the forearm when making this radiological view. Six volar locking plates were inserted at the wrists of cadavers.
The actual screw length was measured under direct vision through
a dorsal approach to the distal radius. Axial radiographs were performed
for different angles of inclination of the forearm at the elbow. Comparing axial radiological measurements and real screw length,
a statistically significant correlation could be demonstrated at
an angle of inclination between 5° and 20°. The ideal angle of inclination
required to minimise the risk of implanting over-long screws in
a dorsal horizon radiological view is 15°. Cite this article:
We undertook a retrospective study investigating
the accuracy and safety of percutaneous pedicle screws placed under
fluoroscopic guidance in the lumbosacral junction and lumbar spine.
The CT scans of patients were chosen from two centres: European
patients from University Medical Center Hamburg-Eppendorf, Germany,
and Asian patients from the University of Malaya, Malaysia. Screw
perforations were classified into grades 0, 1, 2 and 3. A total
of 880 percutaneous pedicle screws from 203 patients were analysed:
614 screws from 144 European patients and 266 screws from 59 Asian
patients. The mean age of the patients was 58.8 years (16 to 91)
and there were 103 men and 100 women. The total rate of perforation
was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade
3 perforations. The rate of perforation in Europeans was 10.4% and
in Asians was 8.6%, with no significant difference between the two
(p = 0.42). The rate of perforation was the highest in S1 (19.4%)
followed by L5 (14.9%). The accuracy and safety of percutaneous
pedicle screw placement are comparable to those cited in the literature
for the open method of pedicle screw placement. Greater caution
must be taken during the insertion of L5 and S1 percutaneous pedicle
screws owing to their more angulated pedicles, the anatomical variations
in their vertebral bodies and the morphology of the spinal canal
at this location. Cite this article:
Bone preservation and physiological distribution of forces on the proximal femur are key elements in introducing a successful uncemented total hip replacement. In order to achieve this, in the mid 1990s, we developed an ultra short proximal loading custom-made component with a lateral flare, a high femoral neck osteotomy and without a diaphyseal stem. We report the outcome of 129 custom-made hydroxyapatite-coated uncemented short femoral components inserted into 109 patients between June 1995 and May 2004. The mean age of the patients was 51 years (21 to 71) and the mean follow-up was eight years (4.9 to 14.1). Bone behaviour around the implant was studied on the post-operative radiographs. The mean Harris hip score improved from 44 (8 to 66) pre-operatively to 95 (76 to 100) at final follow-up. The Western Ontario MacMaster University Osteoarthritis index was 93 of 100 at final review. None of the patients reported thigh pain. A total of five hips were revised, three for polyethylene liner exchange and two for complete revision of the acetabular component. No femoral components were revised. The radiological changes in the proximal femur were generally good, as evidenced by spot welds both on the medial and lateral aspects of the femur. No component migrated. The presence of a lateral flare and use of a high osteotomy of the femoral neck provided good clinical and radiological results. The absence of a diaphyseal portion of the stem did not impair stability.
